Underwater platform



Dec. 15, 1964 P. L. BALISE, JR

UNDERWATER PLATFORM Filed June 20. 1960 JNVENTOR. PETER L. BALISE, JR. BY

g. ATTORN YS.

United States Patent Oil-ice 3,161,255 l atented Dec. 15, 1964 3,161,255 EJNDERWATER PLATFORM Peter L. Baiise, Jr., Seattle, Wash., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed June 20, 1960,'Ser. No. 37,536 2 Claims. (Cl. 181.5)

This invention, relates to apparatus for use in torpedo test ranges for supporting an array of acoustic devices in a level position adjacent the floor of a body of water,

and more particularly to such apparatus having particular a utility in connection with ranging equipment of the type which provides torpedo position data in terms of a three dimensional cartesian system, where it is critical that the acoustic device array be maintained substantially fixed in space with relation to the surrounding Water medium and in a predetermined attitude relative to a horizontal plane.

culties caused by an uneven or sloped floor.

Another object is to provide apparatus in accordance with the first mentioned objective which is not subject to diliiculties caused by settling in mud or silt.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

MG. 1 is a side elevation of the device of the present invention,

FIG. 2 is a section taken along line 22, FIG. 1, and

FIG. 3 is a diagrammatic view, in part in perspective,

showing the device of FIG. 1 employed in determining v the position of a torpedo in terms of a three dimensional cartesian co-ordinate system.

Referring to the drawing and particularly to FIG. 1, submersible apparatus 10, exemplary of the present invention and shown in its normal position of equilibrium when submersed, generally comprises a weight 12, a

spherical buoyant chamber 14- connected to weight 12 by a rigid arm 16, and a framework 18 ah'ixed to chamber 14. Weight 12 has sufficient mass to overcome the positive buoyancy of chamber 14, causing apparatus 10 to sink and serving as its anchor. 7 At its lower end, arm 16 is connected to weight 12 by a suitable pivotal connection permitting arm 16 to pivot in all vertical planes but maintaining it rigid against rotation about its longitudinal axis, such as a Cardan type universal joint 20 having perpendicular horizontal axes A and B. Such connectionpermits arm 16 to adjust itself to a position of equilibrium independent of the attitude of weight 12 v in the event the weight comes to rest on a sloped or uneven portion of the floor of the body of water. Arm 16 is of suflicient length to maintain chamber 14 above the floor of the body of water in the event of a progressive settling of weight 12 in mud or silt. Chamber 14 is connected to the top end of arm 16 by a connection or joint 22 like joint 20 having perpendicular horizontal axes C with the preceding objective which is not subject to difliprising hydrophone R0 at point 0 and hydrophones RX, RY and RZ equ-idistantly spaced from point 0 along reference axes OX, CY and OZ of a three dimensional rectangular cartesian coordinate system with its origin at point 0 and with the plane XOY perpendicular to diametric axis E. Framework 18 may be of any form and in any suitable disposition with relation to chamber 14 which does not impose an excessive weight moment about axes C and D. Two acoustic projectors 26, 28 are also carried by the framework, each tuned to a different frequency, which penmits selectively exciting transponders with different receiving frequencies, as will be better understood in connection with the description of the operation to follow. Chamber 14 is so chosen to provide sufficient positive buoyancy to maintain itself and the framework in stable equilibrium against underwater currents or other effects tending to cause pivoting about axes C and D and thereby maintain plane XOY in a horizontal attitude. A cable 36 provides electrical communication between the hydrophones and projectors, and a remote station located onshore or on a vessel containing other components of the ranging equipment, the weight to cable 30 being in part supported by a strain relief chain 31 attached to arm 16. 'If desired, there may be provision of suitable preamplifier units for the hydrophone receivers within chamber 14 with'the cable leading in and out of the chamber wall through a suitable connector. 1

As an example of the environment in which device 10 is used, it is to be assumed that a torpedo 32, FIG. 3, which carries a conventional transponder 34 is traveling through a test range including apparatus 3i). At suitable intervals a signal from the remote station through cable 30 actuates one of projectors 26 or 28, depending upon which is tuned to the transponder receiving frequency transmitting a substantially omnidirectional acoustic pulse through the water medium to transponder 34 as represented by arrow 36. Transponder 34 replies with an omnidirectional pulse at the receiving \frequency of hydro-phones RO,'RX, etc, which travels through the water as represented by arrows 3S reaching the hydrophones at dilferent instants of time depending upon respective distances between the transponder and the individual hydrophones, which distances are trigonometric functions of the spacing of the hydrophones on the array. The return pulses received by the hydrophones are instantaneously relayed to the remote station through cable 30 where electronic ranging equipment such as disclosed in the aforesaid copending application converts the time differences in receipt of the pulses into torpedo position data in terms of cartesian coordinates with relation to axes OX, OY and OZ. Since apparatus 10 maintains plane XOY horizontal with no rotation about axis E such position data, when accumulated at successive intervals of time may. be presented in terms of the horizontal and vertical trajectory of the torpedo. If desired the other of projectors 26, 28 may be tuned to operate at the frequency of a second transponder which may be carried by a target so that acoustic tracking of the torpedo target may be carried on simultaneously.

If desired apparatus 10 may be provided with means for raising chamber 14, framework 18 and the end of cable 30, for replacement of components or repair. Such means may comprise an electrically actuated severable element 40 in arm 16, shown in dotted lines, such as an explosive element or an electrolytic link, which may be actuated from the remote station via a section of cable 4 communicating with cable 30.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

3 What is claimedis: 1. In an underwater acoustic array of the type having a plurality of spaced acoustic devices rigidly affixed to a buoyant chamber and adapted to be maintained in a substantially fixed position in space near the bottom of a body 0:1 water irrespective of currentof the Water, the improvements, in combination, comprising;

(a) an anchor adapted to be disposed on thefloor of the body of water, (b) a rigid elongated arm disposed between said anchor and chamber, and (0) universal joints connecting opposite ends of said arm to said anchor and chamber, having'pivotal axes which permit the longitudinal axis of saidarm to remain in a position away from the vertical in accordance with forces of the current and irrespective of relative movement at its ends with respect to said anchor and chamber, (d) said universal joints also being so constructed to prevent rotation of said arm about its longitudinal aXlS,

type.

References Cited by the Examiner UNITED STATES PATENTS Mundy 181-05 Gr-ay 18l0.5 Williams 3402 Fay ISL-05 Harrison 3402 Kuntze 1810.5 Babb et a1 1810.5 Van Atta 3402 20 SAMUEL FElNBERG, Primary Examiner.

CHESTER L. JUSTUS, C. W. ROBINSON, Examiners. 

1. IN AN UNDERWATER ACOUSTIC ARRAY OF THE TYPE HAVING A PLURALITY OF SPACED ACOUSTIC DEVICES RIGIDLY AFFIXED TO A BUOYANT CHAMBER AND ADAPTED TO BE MAINTAINED IN A SUBSTANTIALLY FIXED POSITION IN SPACE NEAR THE BOTTOM OF A BODY OF WATER IRRESPECTIVE OF CURRENT OF THE WATER, THE IMPROVEMENTS, IN COMBINATION, COMPRISING; (A) AN ANCHOR ADAPTED TO BE DISPOSED ON THE FLOOR OF THE BODY OF WATER, (B) A RIGID ELONGATED ARM DISPOSED BETWEEN SAID ANCHOR AND CHAMBER, AND (C) UNIVERSAL JOINTS CONNECTING OPPOSITE ENDS OF SAID ARM TO SAID ANCHOR AND CHAMBER, HAVING PIVOTAL AXES WHICH PERMIT THE LONGITUDINAL AXIS OF SAID ARM TO REMAIN IN A POSITION AWAY FROM THE VERTICAL IN ACCORDANCE WITH FORCES OF THE CURRENT AND IRRESPECTIVE OF RELATIVE MOVEMENT AT ITS ENDS WITH RESPECT TO SAID ANCHOR AND CHAMBER, 